Improvement in balanced slide-valves



2 Sheets--Sheet 1,.' E. D. SPEER.

Balanced Slide-Valves. y A No.147,993.- Parentedsfeb.24,1s74.

{JG-Venol EDWARD D. SPEER, OF BROOKVILLE, INDIANA, ASSIG-NOR TO GEORGEK.

l TAYLOR, OF CINCINNATI, OHIO.

IMPROVEMENT IN BALANCED SLIDE'VALVES.

Specification forming part of Letters Patent N o. 147,993, datedFebruary 24, 1874; application filed January 3, 1874.

To all whom t may concern:

Be it known that I, EDWARD D. SPEER, of Brookville, Franklin county,Indiana, have -invented a certain new Improvement in BalA the sides ofthe chest, and form a close steamjoint to prevent leakage, and at thesame time admit of adjustment while running.

Figure l is a perspective View of a cylinder, steam-chest, and valveembodying my invention. Fig. 2 is a horizontal section through the steamchest and valves. Fig. 3 is a crosssection through valves.

A is the steam-cylinder, having steamports B at each end, leadingseparately into the sides of the steam-chest, in manner shown, and ateach side of the same. The exhaust-ports O are also on each side of thesteam-chest, and made to join in one pipe to carry off the exhaust steamin the ordinary way. The valve is composed of two part-s, D D', each ofwhich acts as a valve independently, and both are employed to give abalanced character to the devices in operation. They are connected to across-head, E, tongued and grooved into the valves, or otherwise soloosely attached as to permit of the expansion or lateral adjustment ofthe valves. The cross-head E is attached to the valve-rod F, which givesmotion to the valve in the ordinary way. To these parts D D of the valveis connected a suitable expanding device, which forces .them tightlyagainst the seats G on each side, which seats contain the ports B O,and, owing to .the

loosely-connected cross-head and presence of such expanding device, thevalves are kept against the seats, so as to preserve a tight joint, theexpanding device bem g so made as to tie the valves together in such away as to prevent either from being forced against its seat by thesteam-pressure. The valves, therefore, when operating, will be perfectlybalanced.

In order to provide for the adjustment of these valves while the engineis running, I construct the expanding device as follows: The inner facesof the valves are inclined to each other, and between them a wedge, H,is

fitted, which has dovetailed tongues h upon while the engine is inoperation; and to this end I attach to the cross-head, by a swiveljoint,as shown, a screw-threaded rod, I, the smooth part of which extendsthrough a stuifing-box, J, in the steam-chest, and the screw part of itmoves into a tapped hole in the wedge. The outer end of the rod I istted with a hand-wheel, K, the rotation of which serves to change therelation of the wedge and valves to each other, so that the valves aremore or less expanded or contracted by its operation; and thisadjustment is permitted during the operation of the engine, and thusprovides for varying expansion of metal in the valves under diiferenttemperatures of the steam. To provide against the accidental rotation ofthis rod I, it is fitted with a crosshead, L, havinga set-screw, M, thecross head moving in the ways or slides N. By the release of theset-screw, the rod is permitted to rotate for adjustment, and by thetightening up of the same an accidental adjustment is prevented.

The valves D Dl have the customary exhaustcavities d to formcommunication between each steam-port B and exhaust-port G alternately.The lower part of the chest, below the valves, is cut away, as shown, soas to let the valves rest only on narrow surfaces, and pressure downwardis thus guarded against.

The seats G may be faced with steel, as shown by letter P in Fig. 2.

A'rnivr Ormea I claimthreaded rod I, operating in the manner and l. TheValves D D', connected together by for the purpose described. I anindependently-adj ust-able wedge, H, and operated by a cross-head, E,and rod F, substantially as specified.

'2. The combination of Valve-seats G with ports B C, adjustabledovetail-grooved valves D Df, adjustable tongued Wedge II, and screw- Intestimony of which invention I hereunto set my hand. EDWARD D. SPEER.

Witnesses JOHN HUNTER, J. L. WARTMANN.

